Overall, if you're the type of person who wants to save money by refraining from paying for a seat assignment, early check-in is your best bet for a not-awful seat. Otherwise, certain airlines (namely, Southwest) reward early birds. With other airlines, however, it may not matter too much either way.
Is it okay to check-in 24 hours before flight?
You can usually check in online starting 24 hours before departure. If checking luggage, you will need to bring your luggage to a staffed counter or checked luggage station once you arrive at the airport. Benefits of online check-in: Avoid potential check-in lines at airport.
Why you shouldn’t check-in early?
What does checking in early do for you?
As an EarlyBird Check-In Customer, you'll have the benefit of an earlier boarding position, a better opportunity to select your preferred available seat, and earlier access to overhead bin storage for your carryon luggage.
What are the pros and cons of online check in?
For a short-haul flight where you are only taking hand luggage, checking in online saves a lot of time and is therefore much better than checking in at the airport. If, on the other hand, you have to check in bulky luggage, it is better to use the classic check-in at the airport for security reasons.
How many hours can check in before flight?
Most airline check-in counters open at least two hours before your flight, and some also offer early and online check-in. We encourage you to check in at least two hours before your departure time.